Italian Researchers Say Freezing Your Weed Is The Best Way To Keep THC High On Long Term Stashes

Marijuana Moment report

Many enthusiasts will tell you the best place to keep cannabis is in an air-tight container stowed somewhere cool and dark. But according to the results of a new four-year study, the freezer may actually be a better place—especially if you’re concerned about maintaining that all-important THC content.

Researchers in Italy were interested in understanding how time and various storage conditions (involving light, oxygen and temperature) affected the chemical composition of high-potency cannabis products. Past studies have also investigated this topic, but the authors of new research published in Forensic Science International last week noted that the potency of cannabis in today’s market is “extremely different” from years past.

Using six cannabis products of herbal and resin materials (which were seized by law enforcement and given to researchers to analyze), the study’s authors created 24 primary samples.

After collecting information about how much THC, CBD and CBN (that is, cannabinol, another non-intoxicating component in cannabis that occurs when THC degrades over time) each sample contained, the researchers stored the samples in four controlled conditions for a period of four years.

The testing conditions differed by light exposure (whether it was light or dark 24 hours) and storage temperature (including at room temperature, refrigerated at 4 degrees Celsius or frozen at -20 degrees Celsius). Over the span of the study period, the samples were tested 14 times.

In a finding that will likely be unsurprising to anyone who has stumbled upon an old stash of cannabis stored in a sock drawer, the study determined that the amount of THC decreased—thus increasing the amount of CBN—in the samples stored at room temperature. In the first 100 days of data gathering, the THC in the marijuana stored in both light and dark spaces at room temperature had degraded by 13 percent and 11 percent, respectively.

Meanwhile, the refrigerated cannabis did show some decline in THC and increase in CBN over time, though not nearly as pronounced as the samples kept at room temperature.

The THC content in the samples stored in below-freezing conditions, however, did not significantly change.

This finding indicates, as the authors write, “that freezing is the best storage condition to avoid the reduction of the cannabinoids content over time.”

As for CBD, the study found that the compound remained “relatively constant over time in all the considered samples.”

The authors point out that their findings could be important for forensic purposes. With their methods, they write, law enforcement may be able to figure out what the THC concentration might initially have been in degraded marijuana.

On a more basic level, the research could also help consumers better plan how to store their cannabis.

That said, with marijuana not exactly that hard to find—it’s not as if prohibition is very effective, and more states are legalizing cannabis stores in any case—most people probably won’t be seeking to intentionally store their supply for multi-year periods.